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extract email adresses from some file (or any other pattern)

Terminal - extract email adresses from some file (or any other pattern)
grep -Eio '([[:alnum:]_.]+@[[:alnum:]_]+?\.[[:alpha:].]{2,6})' file.html
2009-06-16 20:19:47
User: wires
Functions: grep
3
extract email adresses from some file (or any other pattern)

find all email addresses in a file, printing each match. Addresses do not have to be alone on a line etc. For example you can grab them from HTML-formatted emails or CSV files, etc. Use a combination of

...|sort|uniq$

to filter them.

Alternatives

There is 1 alternative - vote for the best!

Terminal - Alternatives
grep -Eio '([[:alnum:]_.-]+@[[:alnum:]_.-]+?\.[[:alpha:].]{2,6})'
grep -aEio '([[:alnum:]_.-\+\-]+@[[:alnum:]_.-]+?\.[[:alpha:].]{2,6})'
2013-06-23 21:52:14
User: binarynomad
Functions: grep
Tags: grep email
1

This will catch most separators in the section of the email:

dot .

dash -

underscore _

plus + (added for gmail)

... and the basic dash '-' of host names.

grep -aEio '([[:alnum:]_.-]+@[[:alnum:]_.-]+?\.[[:alpha:].]{2,6})'
2013-05-30 07:17:32
User: nabil_kadimi
Functions: grep
0

The -a option in -aEio tells grep to treat binary files as text files.

Know a better way?

If you can do better, submit your command here.

What others think

I noticed none of these catch the '+' that is allowed in Gmail addresses:

johndoe@gmail.com can freely add a plus and any word afterwards (johndoe+maillist@gmail.com) and it is considered valid.

http://gmailblog.blogspot.com/2008/03/2-hidden-ways-to-get-more-from-your.html

Comment by binarynomad 66 weeks and 4 days ago

People really should take the time to read RFC822 and RFC1035.

This regex is too limited in the username (e.g., plus signs are valid) and is simultaneously too permissive and too limitedin the domain name (underscores are not valid; dashes are and gTLD's can be longer than 6 chars).

To see how insane it is to try and create a single regex that correctly validates RFC822-compliant email addresses, here's one: http://www.ex-parrot.com/~pdw/Mail-RFC822-Address.html

I'd rather see a regex that was too permissive in the username and correct in the domain name. That way it's more likely to catch valid email addresses and bypass false positives.

Comment by KlfJoat 22 weeks and 5 days ago

Your point of view

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